Brad's questions

I'm not familiar with CentOS and I need help doing the routing for this. I have a CentOS box with 3 NICs.

eth0      Link encap:Ethernet  
          inet addr:10.50.121.16  Bcast:10.50.121.255  Mask:255.255.255.0


eth1      Link encap:Ethernet  
          inet addr:10.50.128.134  Bcast:10.50.128.255  Mask:255.255.255.0

eth2      Link encap:Ethernet  
          inet addr:10.50.140.97  Bcast:10.50.140.255  Mask:255.255.255.0

eth0 was an existing interface and it has the default route, I've added eth1 and eth2. There are gateways on eth1 and eth2 segments (the .1 address on both). I need to have some network flows between the eth1 and eth2 NICs (through their respective gateways) to do some testing. So I guess I need to set up policy routing for this?

Edit: Sorry to be clear, I'm not saying I'm trying to route packets between the two new interfaces. I need to send some packets out from eth1's IP to eth2's IP through some infrastructure (thus simulating a conversation between vlan of eth1 and vlan of eth2). So I want to do this eth1 -> eth1-vlan-router -> ??? -> eth2-vlan-router->eth2 and then be able to reply using the reverse route. My bad for not being completely clear here.

So my company has a number of domains with a large registrar that shall go unnamed. We are making some changes to our DNS infrastructure and the first of those is we are moving our secondary DNS from one server on site to four servers offsite. So we updated the name servers for each domain at the registrar by removing the entry for the old secondary name server and adding the four new ones. I monitored the old secondary server for requests and when I saw no new requests had been made for 24 hours I shut it down. That was this morning. I assumed at this point everything was good. Unfortunately this was my mistake. I should have gone and made sure name servers at large were returning the correct NS records.

So this afternoon we were performing maintenance on our primary DNS server and we shut it down. This is when I started getting alerts from our external monitoring. I checked and sure enough, the DNS server used there reported the only NS record for our primary domain was the primary name server. The new secondary servers were not listed and neither was the old secondary.

Is it unreasonable of me to have assumed that because the update was from

ns1.mydomain.com
ns2.mydomain.com

to

ns1.mydomain.com
ns1.backupdns.com
ns2.backupdns.com
ns3.backupdns.com
ns4.backupdns.com

in one step at the registrar that there should be no intermediate state where the only NS record was for ns1.mydomain.com?

Going forward to be safe obviously I will always leave the old name servers alone until after I'm 100% sure the new ones have propagated and only then remove the old name servers from the registrar. However, I'd still like to know if my registrar screwed up or if my expectation was unreasonable.

Basically, what I need is super similar to the unanswered cisco forum question below: https://supportforums.cisco.com/message/3139749#3139749

I have a Cisco 850 Series router. I have configured a DHCP pool for the 10.0.0.0/24 network. I have excluded 10.0.0.1 - 10.0.0.99 from the DHCP pool. I want to add a static DHCP pool for stuff and I want DHCP to statically assign them the addresses of my choice below 100. Actually, I don't care what addresses I statically assign. They can be anything in the pool for all I care, I just want it to work.

Why are you doing this? Just statically assign the IPs on the devices!

I don't want to do this because I have some laptop users. They could obviously only use that static IP here. This isn't a problem if they could be bothered to change any location setting or something. They can't. So it HAS to be DHCP. It also has to be static IPs because I need to forward ports to them. I know, I know, this is weird but it's an apartment LAN/WLAN so this isn't exactly a typical use case.

Relevant sections of config below:

ip dhcp excluded-address 10.0.0.1 10.0.0.99
!
ip dhcp pool Internal-net
   import all
   network 10.0.0.0 255.255.255.0
   default-router 10.0.0.1 
   domain-name 1770.local
   lease 7
!
ip dhcp pool static-pool
   import all
   origin file flash://staticmap
   default-router 10.0.0.1 
   domain-name 1770.local

Contents of staticmap:

*time* Aug 5 2010 09:00 AM
*version* 2
!IP address Type Hardware address Lease expiration
10.0.0.100/24 1  001f.5b3e.d50a   Infinite
*end*

You can see here I was trying addresses outside the excluded-address range to see if that would make any difference.

My testing machine's MAC:

mainframe:~ brad$ ifconfig en1
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    ether 00:1f:5b:3e:d5:0a 

What shows up in the DHCP binding table:

basestar#show ip dhcp binding 
Bindings from all pools not associated with VRF:
IP address          Client-ID/          Lease expiration        Type
            Hardware address/
            User name
10.0.0.112          0100.1f5b.3ed5.0a       Aug 12 2010 10:06 AM    Automatic

What's up with the funny looking MAC in the DHCP binding table??

Is what I'm trying to accomplish basically impossible?

Am I going about this the wrong way? All I want to to be able to port forward some ports to specific devices. The way I would do this with a consumer router is to do what I'm trying to do here; assign static DHCP to those devices then configure PAT for ports on those addresses.